and thinks for himself. His creators (创造者) predict that the robot will be in people's homes before 2040.

　　This $16,000 robot knows who you are. NAO can even express emotions (表达情感). He is a self-guided robot. A self-guided robot can sense (感觉), think and act. Other robots might do two out of the three. For example, a robot might sense things using cameras and think using computers, but with no arms, he can't act. Another robot can move and sense things, but he can't think for himself. These aren't self-guided robots. But NAO can do them all.

根据材料内容选择最佳答案。

51. The underlined word "greets" means "_____" in Chinese.

A. 讨厌 B. 击败 C. 迎接 D. 仰慕

52. The robot tells you to _____ to your cousin.

A. say happy birthday

B. dance

C. send a birthday gift

D. write

53. What does NAO look like?

A. He has small eyes and a small head.

B. He has big eyes and a large head.

C. He has a large body with a large head.

D. He has a small body with a small head.

54. When might people have robots like NAO in their homes?

A. In 2020. B. In about 15 years.

C. In 2030. D. In about 30 years.

55. Which of the following is TRUE according to the passage?

A. NAO isn't a self-guided robot.

B. NAO can't help kids with their homework.

C. NAO is more than fifteen thousand dollars.

D. NAO can move and sense, but he can't think.